Interpretive Summary: Modern agriculture often assumes that there is little connection between the soil and human health. Nutrients for crop growth are supplied by fertilizers and disease or poisonings from soil are only in developing countries or due to industrial pollution. However, there is a long history of recognition that soil properties are in fact closely related to human health. Ancient Greeks included selected soil properties as being related to good health. European settlers in America would choose where to set up their homes and farms based on their perceptions of the productivity and health of the land. There is a growing interest in the relationship of soil properties with human health. One area of interest is with regard to nutrition. Analyses of crops show different nutrional value that can be traced back to soil properties. Greater understanding of some diseases has included the role of soil either in transmitting or as a reservoir for pathogens. Some chemicals in soil, either from human activity like lead from leaded gasoline or natural like arsenic from groundwater, have also been the subject of increased attention regarding methods to prevent or alleviate human health risks due to chemical exposure. Research in this area is complicated and challenging because soil scientists and medical professionals are unaccustomed to working together and share little common expertise. Future efforts, including additional challenges created by climate change, will require greater communication and cooperation between soil scientists and medical professionals. This research is important to scientists, resource managers, and citizens interested in reducing or preventing human health effects due to poor nutrition, soil-borne diseases, and chemical exposures.

Technical Abstract:
The idea that human health is tied to the soil is not a new one. As far back as circa 1400 B.C. the Bible depicts Moses as understanding that fertile soil was essential to the well-being of his people. In 400 B.C. the Greek philosopher Hippocrates provided a list of things that should be considered in a proper medical evaluation, including the properties of the local ground. By the late 1700s and early 1800s, American farmers had recognized that soil properties had some connection to human health. In the modern world, we recognize that soils have a distinct influence on human health. We recognize that soils influence 1) food availability and quality (food security), 2) human contact with various chemicals, and 3) human contact with various pathogens. Soils and human health studies include investigations into nutrient supply through the food web and routes of exposure to chemicals and pathogens. However, making strong, scientific connections between soils and human health can be difficult. There are multiple variables to consider in the soil environment, meaning traditional scientific studies that seek to isolate and manipulate a single variable often do not provide meaningful data. The complete study of soils and human health also involves many different specialties such as soil scientists, toxicologists, medical professionals, anthropologists, etc. These groups do not traditionally work together on research projects, and do not always effectively communicate with one another. Climate change and how it will affect the soil environment/ecosystem going into the future is another variable affecting the relationship between soils and health. Future successes in soils and human health research will require effectively addressing difficult issues such as these.